Faces masked, dressed in black, and forcefully attacking the symbols of capitalism, Black Blocs have been transformed into an antiglobalization media spectacle. But the popular image of the window-smashing thug hides a complex reality. Francis Dupuis-Deri outlines the origin of this international phenomenon, its dynamics, and its goals, arguing that the use of violence always takes place in an ethical and strategic context. This text has been translated into English for the first time and is completely revised and updated to include the most recent Black Bloc actions at protests in Greece, Germany, Canada, and England, and its role in the Occupy movement and the Quebec student strike. It lays out a comprehensive view of the Black Bloc tactic and locates it within the anarchist tradition of direct action.